As a professional software engineer with over 20 years in the industry, I disagree. The ones getting paid are usually more laid back than the amateurs. I have my paycheck, resume, and credits - I don't need to prove anything. There are also those in my industry who are only competitive in terms of padding and lying on their resume's.
An amateur, on the other hand, actually CARES about what they are doing. They might do it for themselves, or just a pat on the back. There's no promise of a paycheck, so the ONLY incentive to do a job is to do it well.
Of course, some of us do it both professionally, and as a hobby. We are, well, true engineers.. the geeks of the world.
(before someone flames me for the use of "amateur"; its not a negative term. It's properly defined as: a person who engages in a study, sport, or other activity for pleasure rather than for financial benefit or professional reasons. Most amateurs are actually better than their professional/paid peers.)